Field of Disclosure
This invention relates to barriers for guarding against horizontal entry of floodwaters through vertical openings in buildings, especially tall ventilation openings.
Background
Floodwaters are a major source of property damage. On Oct. 29 and 30, 2012 tropical storm Sandy struck New York City, its suburbs, and Long Island. Supplemented by a high tide, the storm surge was approximately 14 feet above mean low tide, overtopping seawalls and bulkheads lining Manhattan and other waterfront boroughs, flooding buildings, subway and vehicle tunnels, damaging electrical equipment, costing at least 48 lives, and in effect shutting down the City. Damages and economic losses across New York were estimated to be at least $33 billion and in neighboring New Jersey, $36.8 billion.
Doors and other grade level vertical openings have been guarded from entrance of water by gates that are self-actuating. See U.S. Pat. No. 6,623,209, by the inventor of the invention described herein. These self-actuating gates should be taller when raised than the projected height of flood waters above sea level, typically taken as the height of flood waters based on 100-year storm data (a 100-year storm is defined as the storm with a 1% percent chance of occurring within a region in any one given year). For example, if the height for a 100-year storm is 10 feet above sea level and the street or sidewalk served by the exit/entrance of a building has a height above sea level of 5 feet, the exit/entrance is vulnerable to flood waters exceeding 5 feet above street level. The top of typical exit/entrances at street level is several feet above six feet, typically 10 feet, so the raised height of a self actuating flood gate of the type described in U.S. Pat. No. 6,623,209 guarding the exit/entrance would have to be at least 5 feet tall for the 100 year storm and at least 10 feet tall for complete protection from flood waters that could reach to as high as the top of the typical exit/entrances opening. Due to constraints inside or outside the exit/entrance of a building, for example, stairs climbing to the level of the exit/entrance, it may not be feasible to install a self-actuating flood gate of the type provided in U.S. Pat. No. 6,623,209 in part at least due to the size of the housing for the gate necessary to accommodate the height the gate would have when raised.
One victim of Sandy was buildings in lower Manhattan with tall vertical louvered ventilation openings in the sides of the buildings starting well above the street level fronting the buildings. The grade of the street level for these victims was 6.6 feet above sea level. The bottoms of the ventilation openings were at least about 20 feet above sea level, yet floodwaters from Sandy scaled higher than the bottom of the ventilation openings and penetrated the interior of the buildings. Certainly in the case of ventilation openings high above street level a housing for a self-actuating flood gate of the type provided in U.S. Pat. No. 6,623,209 installed at grade level and a 20 foot tall flood gate normally would not be practicable.
The present invention provides a self-actuating gate that overcomes these constraint limitations.